Ice Wall Jumping

With proper timing, you can jump, create an ice wall, land on the created ice wall, and jump again. This is used in a variety of places across the speedrun, so it is a vital piece of tech. Screens can still be completed without it, but you will lose significant amounts of time.

you have to use the ice wall a short time after jumping, but also high enough to reach your destination.

Multiple Ice Wall Jumps

Because pausing and switching weapons despawns attacks (including ice walls), it is possible to jump off an ice wall, pause, switch away from ice wall, and after unpausing immediately switch back to ice wall to wall-jump again.

This is slow, but can be useful for large vertical climbs or to ignore cycles.